The present invention relates to subterranean operations. More particularly, the present invention relates to solid nano-particles applied to the surface of well equipment to treat bituminous material adhesion.
Many subterranean operations involve the drilling of a well bore from the surface through rock and/or soil to penetrate a subterranean formation containing fluids that are desirable for production. In the course of drilling operations and other subterranean operations, the drill string and/or other equipment and tools may come into contact with zones of rock and/or soil containing tar and/or heavy oil, such as heavy and light (liquid) hydrocarbons, asphalt, and bitumen; collectively referred to herein as “bituminous materials;” wherein these zones are collectively referred to herein as “bituminous sand zones.” In many such operations, it may be desirable to drill the well bore through these bituminous sand zones. However, problems may be encountered when drilling through bituminous sand zones. For example, bituminous materials are typically relatively tacky substances that may adhere to any surfaces they contact. In addition, bituminous materials may dissolve into many types of treatment fluids used in the course of drilling operations, increasing the tackiness and adhesive properties of the bituminous materials. If a sufficient amount of bituminous materials adheres to surfaces in the well equipment, it may, among other problems, prevent the drillstring from rotating, prevent fluid circulation, increase non-productive time, create torque and drag issues, cause tool damage, or otherwise impede the effectiveness of a drilling operation. In some cases, it may become necessary to remove and/or disassemble the drillstring in order to remove accretions of bituminous materials, a process which may create numerous cost and safety concerns. The accretion of bituminous materials on drilling equipment and/or in the well bore also can impede any subsequent operations downhole, including cementing, acidizing, fracturing, sand control, and remedial treatments. In addition, soft, tacky bituminous materials that manage to reach the surface may foul surface equipment, including solids screening equipment and solids control equipment, for example, by binding shaker screens.
Existing methods of managing the problems that result from well bore bituminous material incursion may be problematic. Examples of conventional methods may utilize treatment fluids that comprise dispersants, surfactants, and/or solubilizers, which allow the bituminous materials to dissolve in or homogenize with the treatment fluids. However, the bituminous materials may not be readily separated out of the fluid once they have dissolved into or homogenized with the fluid. The presence of the bituminous materials in the treatment fluid may alter its rheological properties and/or suspension capacity, which may limit its use in subsequent operations. Moreover, the addition of these dispersants, surfactants, and solubilizers may increase the complexity and cost of the drilling operation.